Battle properties

Generation I

Generation II onwards

Characteristics

Defense

Prior to Generation VI, Steel/Psychic types were exempt from Psychic's three weaknesses, but since Steel no longer resists Dark and Ghost, this is no longer the case.

Offense

A drawback of Psychic-type moves is that they do not affect Dark-type Pokémon, although this immunity can be removed with Miracle Eye. The immunity, along with resistances to Psychic, can also be circumvented with coverage moves such as Ground-type attacks.

Contest properties

When used in Contests, Psychic-type moves are typically Clever moves, but can also be of the other four Contest types, excluding Tough.

Generation I balance issues

In the Generation I games, Psychic-type Pokémon were at the center of a balance issue.[1] As a result, the issue was rectified in Generation II, with the addition of Steel and Dark types, an added weakness to Ghost-type moves (as opposed to previously being immune to them), as well as some moves that are strong against Psychic types.

Pokémon

As of Generation VII, there are 85 Psychic-type Pokémon or 10.5% of all Pokémon (counting those that are Psychic-type in at least one of their forms, including Alola Forms), making it the 5th most common type.

In the TCG

Due to the decreased amount of types in the TCG, Psychic generally adopts all Ghost-type Pokémon under its typing. It also adopted Poison-type Pokémon after the Diamond & Pearl set, whereas previously they were a part of the Grass-type.

Similar to the games, Psychic-type Pokémon in the TCG are generally weak to other Psychic Pokémon, with no resistances. Psychic-type Pokémon are strong against Grass (until Diamond & Pearl), Fighting and Psychic Pokémon, whilst Colorless, Darkness and Metal Pokémon can resist this type.

Trivia

Generation III introduced the most Psychic-type Pokémon of any generation, with 20, and Generation VI introduced the fewest Psychic-type Pokémon, with six.

Generation I introduced the most Psychic-type moves of any generation, with 15, and Generation VI introduced the fewest Psychic-type moves with only one.

Psychic is the most common type for Legendary and Mythical Pokémon, with at least two Psychic-type Legendary or Mythical Pokémon introduced in each generation (except Generation VI, which only introduced one) for a total of 19 (out of 71).

The Psychic type is the only former special type to not have any of its old moves changed into physical moves, while the Fighting type is the only former physical type to not have any of its old moves changed into special moves.

References

↑ Sugimori, Ken "Psychic Pokémon seemed to dominate in the previous Pokémon game, so we needed to come up with new Pokémon and types to make Pokémon Gold and Silver more balanced." Nintendo Power 134 (July 2000) p. 79 (retrieved August 16, 2010)